Matrix display devices

ABSTRACT

A matrix display device, for example an AMLCD, has first and second spaced substrates ( 22, 23 ) carrying opposed display pixel electrode structures ( 14, 32, 38 ) defining a pixel array/display area ( 20 ) with the first substrate ( 22 ) further carrying outside the display area auxiliary circuitry, for example, comprising row and column drive circuits ( 40, 42 ) a signal processing circuit ( 45 ) a memory circuit ( 47 ), or control logic circuit ( 46 ). At least a part of the auxiliary circuitry is electrical shielded to prevent electrical interference problems by an electrically conductive shielding layer(s) ( 60 ) carried on a part ( 50 ) of the first substrate ( 23 ) that extends over the auxiliary circuitry. The shielding layer may conveniently comprise part of an electrode layer ( 32 ) deposited on the second substrate and used for the pixel electrode structure.

The present invention relates to a matrix display device comprisingelectro-optic material disposed between first and second spacedsubstrates, the first substrate carrying a pixel circuit comprising anarray of pixel electrodes defining display pixels in a display area andauxiliary electronic circuitry at a region of the first substrateoutside the display area.

An example of such a display device is an active matrix liquid crystaldisplay device (AMLCD). As is well known, these devices comprise a layerof liquid crystal material sandwiched between a pair of spacedsubstrates which are sealed together to contain the liquid crystalmaterial and carry electrodes that define individual display pixels in arow and column array. One of the substrates, commonly referred to as theactive substrate or plate, carries an array of pixel electrodes each ofwhich is associated with a switching device, typically a thin filmtransistor (TFT), provided on the substrate adjacent to the pixelelectrode. The substrate also carries sets of row and column addressconductors connected to the TFTs to enable addressing of the pixels. Theother substrate, commonly referred to as the passive substrate or plate,carries an electrode structure constituting the display pixel secondelectrodes, and usually provided as a single conductive layer forming acommon electrode extending over the array of pixel electrodes in thedisplay area. The passive substrate typically also carries an array ofcolour filter elements, each associated with, and overlying, arespective pixel electrode on the active substrate, and a black matrix,light shielding layer comprising a grid of optically opaque materialextending between the individual colour filter elements of the displaypixels.

Commonly, drive circuits for driving the display pixels are provided inthe form of ICs mounted on the active substrate peripherally of thedisplay pixel array whose outputs are connected to the sets of addressconductors. It is known also to integrate the drive circuits on theactive substrate as thin film electronic circuits comprising circuitelements such as switching devices and connection lines fabricatedsimultaneously with the switching devices (TFTs) and address conductorsin the pixel array from common deposited layers. Such integration avoidsthe need to provide separately fabricated drive circuits and to connectthese with the sets of address conductors. Both the row (scanning) drivecircuit for selecting rows of display pixels and the column (data) drivecircuit for supplying display data signals to the pixels to obtain adesired display output from individual display pixels can readily beintegrated using conventional polysilicon technology. A typical exampledevice using integrated drive circuits is described in the paperentitled “Fully Integrated Poly-Si TFT CMOS Drivers for Self-ScannedLight Valve” by Y. Nishihara et al in SID 92 Digest, pages 609-612.

More recently, it has been proposed that additional circuit functionscan similarly be integrated on the active substrate, for example,circuitry for voltage level generation, memory and video signalprocessing functions, which hitherto have been implemented in circuitryprovided separately from the active substrate. An example of an AMLCDwith additional, integrated, auxiliary circuit functions is described inthe paper entitled “A Highly Integrated AMLCD for Mobile PhoneApplications” by M. J. Edwards et al, Digest of Technical Papers inAM-LCD 01 (2001 International Workshop on Active—Matrix Liquid—CrystalDisplays, Japan), pages 53-54. In this, dynamic memory circuits areincorporated in the pixels and additional circuitry, comprising chargepump circuits for generating voltage levels required in operation, acontrol logic circuit for controlling the operation of the row andcolumn drive circuits, and a common electrode drive circuit, areintegrated on the active substrate at its periphery outside the pixelarray area, and fabricated using thin film processing technology. Such adevice requires only a minimum of external connections, to provide lowvoltage digital video data signals and a low voltage power supply ofaround 3.3 volts.

The additional circuitry integrated on the active plate may be expected,however, to lead to problems associated especially with electromagneticinterference and noise effects, particularly as the complexity,functionality and performance of the circuits increases. These may beproblems caused by the radiation of electrical noise from the circuitswhich become more apparent as circuit operating frequencies increase,for example, as a consequence of increasing the size and/or resolutionof the display device. On the other hand, problems may be experienceddue to the sensitivity of these circuits to external sources ofelectrical interference, particularly if the circuits are operating withrelatively low voltage signal levels.

According to the present invention, there is provided a matrix displaydevice as described in the opening paragraph wherein the secondsubstrate extends over at least part of the auxiliary circuitry on thefirst substrate and carries an electrically conductive shielding layerfor electrically shielding at least a region of the auxiliary circuitry.

Thus, electrical shielding serving to prevent, or at least reduce, aproblem with electrical interference caused by, or in, the auxiliarycircuitry during operation of the device is provided in a relativelysimple and convenient manner and requiring minimal additional componentsand processing.

The auxiliary circuitry preferably includes drive circuits for drivingthe display pixels, i.e. a row (scanning) drive circuit and a column(data) drive circuit.

Where the display device has an electrode layer on the second substrateoverlying the pixel electrode array, for example, a common electrode forthe display pixels in an active matrix liquid crystal display device,(which may be a continuous electrode extending over the entire displayarea defined by the pixel array or, alternatively, of a sub-divided formcovering respective different regions of the array), the conductivelayer provided on the second substrate for this purpose, and typicallycomprising a transparent conductive material such as ITO, mayadvantageously be utilised to provide the conductive shielding layer.Accordingly, the shielding layer is provided without any additionalcomponents or deposited layers being necessary, thereby simplifyingmanufacture.

Preferably, where the second substrate is of the kind that carries ablack matrix, light shielding, layer and this layer comprises materialwhich is electrically conductive, for example a metal such as chromium,then this material may similarly be used to provide the electricallyshielding layer, either alone or possibly together with the commonelectrode layer material, preferably as overlying layers. Enhancedshielding can then be achieved by virtue of this metal having a lowersheet resistance compared with ITO.

The electrically shielding layer is preferably separated electricallyfrom the common electrode layer and/or the black matrix layer extendingover the pixel array. This separation enables the potentials applied tothe different regions in use to be independently controlled.

In a particularly preferred embodiment, where the auxiliary circuitrycomprises a plurality different circuits performing respective functionsand occupying respective, discrete, regions of the first substrate, forexample, row and column drive circuits positioned adjacent respective,different, edges of the display area and further associated circuits atother areas, the electrically shielding layer comprises discrete,physically separate, portions, each of which portions overlies, eithercompletely or partially, a respective one or more of the differentcircuits. This division would assist in avoiding interference betweenthe different circuits. The shielding layer covering the differentcircuits could be provided as a single, continuous, conductive layer butin this case it would not be possible to control independently thepotentials applied to the layer portions overlying individual associatedcircuits and the risk of interference occurring between differentcircuits would be increased.

Although the invention is applicable especially to matrix liquid crystaldisplay devices, and particularly active matrix liquid crystal displaydevices (AMLCDs), it is envisaged that it could be applied to advantagein display devices using other kinds of electro-optic materials andsimilarly using two, spaced, substrates.

In the case of an AMLCD or similar having a seal between the twosubstrates extending around at least the display area for containingelectro-optic material, the auxiliary circuitry may be situated outsideor inside the seal line. In the former case, a further one or more sealsmay be provided between the substrates and extending around the, orrespective parts of, the auxiliary circuitry for protecting thecircuitry. Alternatively, parts of the auxiliary circuitry, for examplerow and column drive circuits, may be situated within the seal linewhile other parts are situated outside the seal line, again with thoseparts outside the seal line preferably being protected by one or moreadditional seals.

An embodiment of matrix display device, in particular an AMLCD, inaccordance with the present invention will now be described, by way ofexample, with reference to the accompanying drawings, in which:

FIG. 1 is a plan schematic view of the display device; and

FIG. 2 is a schematic cross-sectional view along the line II-II of FIG.1.

It will be appreciated that the figures are mere schematic and are notdrawn to scale.

The AMLCD is of a conventional kind as regards its general constructionand operation and accordingly it is not considered necessary to describehere these aspects in detail. Referring to the figures, the devicecomprises a matrix array of individual display pixels 10, the circuitconfiguration of a typical one of which is shown enlarged in FIG. 1.Each pixel comprises a pixel electrode 14 and an associated switchingdevice 16, here in the form of a thin film transistor (TFT). The pixelelectrode 14 is connected to the drain of the TFT while the gate andsource of the TFT are connected to respective ones of sets of row andcolumn address conductors 17 and 18 shared by the pixels in the array.

The display pixels 10, organised in rows and columns, occupy a pixelarray area between two overlying substrates 22 and 23 and defining acorresponding display area 20. Referring also to FIG. 2, the twosubstrates 22 and 23 are spaced apart and sealed together around theperiphery of the display area 20 by a seal 24 to contain a layer oftwisted nematic liquid crystal (LC) material 25 therebetween. The sealline corresponds approximately with the edge of the common electrode 32.Both substrates are of glass although other insulating materials,including flexible polymer materials or materials with an insulatingsurface, may be used, and, in the case of a reflective rather thantransmissive type of display, only one needs to be optically transparentto transmit light in operation.

The substrate 22, referred to as the active substrate, carries theactive matrix circuitry of the display array, which circuitry comprisesthe sets of row and column address conductors 17, 18 and the TFTs 16,and also the pixel electrodes 14. The active matrix circuitry and pixelelectrodes are formed on the inner surface of the substrate 22 inconventional manner using large area, thin film, processing techniquesinvolving the deposition and patterning of various conducting,insulating, and semiconducting layers deposited over the substrate, forexample by a CVD process, and using photolithographic definitiontechniques, as is well known in the art. The TFTs 16 used here arepreferably of the polysilicon type with either top or bottom gatestructure. An LC orienting film 26 is provided over the active matrixpixel array in normal fashion.

The other substrate 23, referred to as the passive substrate, carries onits inner surface adjacent to the liquid crystal layer 25 a transparent,electrically conducting, layer 32, for example of ITO, which extendscontinuously over the display area 20, corresponding to the array of thearray of pixel electrodes 14, and serves as a common electrodeconstituting opposing electrodes of the display pixels in the array.Each display pixel thus comprises a first electrode 14, a secondelectrode constituted by the overlying portion of common electrode layer32, and the intervening liquid crystal layer 25. A further LC orientingfilm 34 is provided completely over the ITO electrode 32. The commonelectrode 32 may instead be divided into a plurality (two or more) ofelectrically—separated portions, each portion covering a respective partof the display area, where it is desired to use a particular kind ofdrive scheme which requires different potentials to be applied to thepixel second electrodes in different regions of the array at differenttimes.

The display device comprises a colour display device. In such devices,it is usual for the passive substrate also to carry an array of red,green and blue colour filter elements aligned with the pixels such thateach pixel is assigned a respective colour output. Alternatively,however, a colour filter array could be provided on the active substrate22 instead. As will be apparent to skilled persons, a variety ofdifferent colour filter element types and structures can be used.Typically, and as shown in FIG. 2, the colour filter structure consistsof a filter layer 36 consisting of red, green and blue portions, asshown at 36A, 36B and 36C, each of which overlies a respective pixelelectrode 14, and black matrix in the form of lines of light opaquematerial extending in the row and column directions and defining a gridpattern 38 surrounding the individual colour filter portions.

In operation of the device, the pixels 10 are driven in a conventionalmanner with each row in the array being addressed in sequence, one at atime in respective row address periods, by means of a scanning (gating)signal applied to each row conductor 17 in turn to turn on the TFTs 16of the pixels in the selected row which allows the pixels to be loadedwith respective data signals, derived from an input video signal andapplied to the column conductors 18 in synchronisation with the scanningsignals, which determine the display outputs of the individual pixels.Upon a row of pixels being selected, the electrode 14 of each pixel 10in the row is thus charged to a level according to the applied datasignal thereby producing a desired display output. Following theaddressing of all the rows of pixels in this manner in one frame periodto provide a display image output, the rows are repeatedly addressedagain in similar manner in successive frame periods.

The scanning and data signals are applied to the sets of row and columnaddress conductors 17 and 18 respectively by row and column drivercircuits 40 and 42 carried on the substrate 22 and forming part ofauxiliary circuitry. These circuits are of conventional type andintegrated on the inner surface of the substrate 22 at the periphery ofthe substrate 22 outside the pixel display area 20. They comprise thinfilm circuit elements, such as TFTs, capacitors and interconnections,fabricated simultaneously with the active matrix circuitry on thesubstrate 22 from the same deposited thin film conducting, insulatingand semiconducting layers used for the active matrix circuitry andsharing the same processing technology. The integration of the drivecircuits is becoming increasingly common in AMLCDs employing polysiliconTFT technology as it avoids the need to mount prefabricated drivecircuits in crystalline silicon IC form either on the substrate 22 or ona separate support with interconnections to the substrate 22.

As shown in FIG. 1, the row and column drive circuits 40 and 42 areformed on respective, discrete, regions of the substrate 22 extendingalong two adjacent sides of the pixel array 20 and outside the seal 24.The row and column address conductors 17 and 18 extend from the pixeldisplay area to the regions occupied by these drive circuits where theyare connected to respective outputs of the drive circuits. In thefigures the driver circuits are schematically represented in block formfor simplicity.

Various electronic circuit functions in addition to the row and columndrive circuit functions and forming part of the auxiliary circuitry canalso be integrated on the substrate 22 outside the display/pixel arrayarea 20 in similar manner, as in the device described in theaforementioned paper by M. J. Edwards et al. In this particularembodiment of display device, additional circuit functions included onthe active substrate 22 comprise a signal processing circuit 45, forperforming corrections and adjustments to an incoming video signal priorto its supply to the column drive circuit 42, a control logic circuit 46for deriving timing information from the incoming video signal andcontrolling the operation of the row and column drive circuits 40 and 42in accordance therewith, and a memory circuit 47, which may be employedfor a variety of purposes requiring the storage of pixel data, forexample, for holding a display image, or as a field store for use inconjunction with the signal processing circuit 45 in performing videodata signal adjustments. Each of these further circuits integrated onthe substrate 22, and again represented in block form in the figures forsimplicity, occupies a respective discrete area on the substrate 22outside the pixel array area towards the periphery of the substrate 22.A layer of passivating material 49 (FIG. 2) is deposited over thecircuits to encapsulate and protect them. Further protection is affordedby an additional seal 52 extending between the substrates 22 and 23 andaround the auxiliary circuitry to enclose and hermetically seal thespace between the substrates in which the auxiliary circuitry iscontained. Separate additional seals may be used for respective parts ofthe circuitry in this way.

It will be appreciated that the auxiliary electronic integratedcircuitry could include other circuit functions in addition to, orinstead of, those particular circuits mentioned (for example asdescribed in the aforementioned paper) depending on the individualdisplay device requirements. Generally, the auxiliary circuitry wouldinclude at least the row and column drive circuits 40 and 42.Interconnections between the different circuits of the auxiliarycircuitry and the pixel array, and external inputs have not been shownin the figures for the sake of clarity.

The auxiliary circuitry may comprise circuits other than the examplecircuits described above, and may be circuits which are not necessarilydirectly associated with the driving of the display pixels. For example,sensing circuits may be integrated on the substrate 23 for sensing touchinputs or the like to the device.

The increased functionality provided in this way requires relativelycomplex circuitry, and, particularly with improvements in theperformance of display devices with such circuitry, for example as aresult of increasing the number of pixels in the array to produce largeror high resolution displays, problems associated with electromagneticinterference effects can become apparent. These problems may be due tothe effects of electromagnetic radiation, or noise, emanating from thecircuits as their operating frequencies are increased. Typically,frequencies in the order of several MHZ may be present in operation ofthe device. Conversely, the circuits themselves may be highly sensitiveand susceptible to electrical interference from external sources. Sucheffects may be especially apparent if the circuits are operating withrelatively low level signals or if only minor variations in signallevels are acceptable.

In order to reduce the aforementioned electrical interference relatedproblems, at least to an extent, the display device is provided withelectrical shielding carried on the passive substrate 23 and extendingover at least part of the auxiliary circuitry constituted by theindividual circuits integrated on the active plate 22. To this end, thesize substrate 23 is increased so as to extend beyond the pixel arrayarea with parts thereof overlying at least those additional circuitswhich it is desired to shield. In the case of the embodiment illustratedin FIGS. 1 and 2, the substrate 23 is extended so as to cover all thecircuits 40, 42, 45, 67 and 47, with the circuits 42 and 45 to 47 beingcovered by an end region 50 of the substrate 23 and the circuit 40 beingcovered by a side region 51. The size of the substrate 23 in the latterdimension substantially corresponds to that of the substrate 22. Theelectrical shielding is provided in the form of an electricallyconductive layer carried on the inner surface of the substrate 23 andoverlying the additional circuits. This layer may be a separate,independently deposited, layer provided on the substrate 23 specificallyfor this purpose, in which case the material of the layer may beselected from a variety of different conductive materials capable ofbeing deposited and patterned in appropriate manner. Preferably,however, the shielding layer is formed from one, or more, of thedeposited conductive layers used to form the structure on the substrate23 at the pixel array area. This greatly simplifies fabrication as noadditional deposition and patterning processes need be involved.Instead, the regions of the deposited layer required for electricalshielding can be defined at the same time as the deposited layer ispatterned to provide the require structure at the pixel array area byemploying, in the case of a standard photolithographic processingtechnique involving resist patterning and etching operations being usedfor this purpose, an appropriately designed patterning mask.

In the embodiment shown, the ITO layer deposited on the substrate 23 andused to form the common electrode(s) 32 of the pixel array isconveniently utilised for the shielding layer, as shown at 60 in FIG. 2.The ITO layer deposited over the substrate 23 is patterned such that theshielding layer 60 and common electrode 32 defined thereby areelectrical separate so as to avoid any interaction between signals inthe pixel array and the operation of the integrated circuits. Moreover,in this embodiment the shielding layer 60 is divided into discreteregions each of which overlies a respective one or more of theadditional circuits. Referring to FIG. 1, then the shielding layer issplit into four separate portions 60A, 60B, 60C and 60D covering,respectively, the column drive circuit 42, the memory and control logiccircuits 47 and 46, the signal processing circuit 45, and the row drivecircuit 40, and each serving to shield individually its respectiveassociated circuits. The common electrode 32 serves as a shield for thepixel array area.

The material used to provide the black matrix 38 in the structure on thesubstrate 23 here comprises a metal such as chromium. The layerdeposited for this purpose may be used also to form the shielding layerrather than the ITO layer. Alternatively, both layers could be used suchthat the shielding layer then has a composite layer structure.

In use of the device, the electrical shielding portions 60A-D are eachheld at a predetermined potential so as to act appropriately aselectrical screening. Typically, this may correspond to ground, althoughother potential levels may be used. The potential level need not beconstant but could vary, for example where potential levels in theunderlying circuit change in a fixed pattern. Even if the samepredetermined potential, e.g. ground, is applied to all portions, it isdesirable for the electrical shielding to be divided into separateportions rather than employ a continuous layer overlying all theadditional circuits so as to avoid, or reduce, the possibility ofinteractions between different circuits, for example with digitalswitching signals in the memory circuit 47 affecting analogue signals inthe signal processing circuit 45. Such division can also assist inreducing power consumption.

In order to apply the appropriate potentials to the electrical shieldingportions 60A-D, electrical connections are provided between the activesubstrate 22 and these portions on the substrate 23, as indicated at 65in FIG. 1. More than one connection may be present for each portion. Asimilar connection(s) is provided also for the common electrode 32.These connections may, for example, comprise electrically conductingpillars of slightly compressible material formed on the active substrate22 and over conductive tracks carried on the substrate 22 which aresupplied with the appropriate potential levels by the integrated powergenerating circuit, and positioned such that when the two substrates 22and 23 are assembled and sealed together, the pillars contact theirrespective shielding portions and the common electrode 32. Other meansof establishing electrical connections between the substrate 22 andthese areas on the substrate 23 can, however, be employed, as will beapparent to skilled persons.

As in conventional AMLCDs, the two substrates 22 and 23 are spacedclosely together, typically with around five micrometers separation, andconsequently the electrical shielding layer portions are in closeproximity to their respective circuits and provide highly effectivescreening for electromagnetic interference effects, thereby preventingthe radiation to the outside of the device of electrical noise generatedby the circuits due especially to the high frequency signals presentwhen operating, or to prevent external electrical noise sourcesaffecting their operation where these circuits may otherwise besensitive to such noise, for example by virtue of being designed tooperate with relatively low level signals. The close spacing of the twosubstrates means that although the sides of the spaces defined by theoverlying parts of the substrates at their edges may be left unshielded,very little or no electrical noise is likely either to reach theintegrated circuits from outside or to escape to the outside throughthese sides.

In the example described, the seal 24 containing the LC material betweenthe substrates 22 and 23 extends around the area of the pixel array andthe auxiliary circuitry is located outside the seal line. However, otherarrangements of seals are possible. Thus, the seal line may instead bearranged to surround certain of the associated integrated circuits, forexample the row driver circuit 40 and/or the column driver circuit 42,so that these circuits are effectively within the LC cell defined by theseal line and the substrates. The seal line may alternatively bearranged close to the edge of the substrate 23 along all sides so as toenclose all the auxiliary circuitry. In this case, the additional sealor seals 52 are unnecessary.

Although the invention has been described in relation to an AMLCD, it isenvisaged that it can be applied to other kinds of display devicessimilarly comprising two spaced substrates with electro-opticalmaterial, for example, an electrochromic or electrophoretic materialdisposed between the substrates and having auxiliary circuits carried onone of the substrates.

From reading the present disclosure, other modifications will beapparent to persons skilled in the art. Such modifications may involveother features which are already known in the field of active matrixdisplay devices and component parts therefor and which may be usedinstead of or in addition to features already described herein.

1. A matrix display device comprising electro-optic material disposedbetween first and second spaced substrates, the first substrate carryinga pixel circuit comprising an array of pixel electrodes defining displaypixels in a display area and auxiliary electronic circuitry at a regionof the first substrate outside the display area, wherein the secondsubstrate extends over at least part of the auxiliary electroniccircuitry and the display area on the first substrate and carries anelectrically conductive shielding layer for electrically shielding atleast a region of said auxiliary electronic circuitry, wherein saidelectrically conductive shielding layer is divided into a plurality ofelectrically separate areas covering respective parts of said auxiliaryelectronic circuitry.
 2. The matrix display device of claim 1, whereinthe electrically conductive shielding layer comprises part of anelectrically conducting layer deposited on the second substrate andforming part of the structure of the display pixels in the display area.3. The matrix display device of claim 2, wherein the parts of theelectrically conducting layer on the second substrate constituting theelectrically conductive shielding layer and the display pixel structureare electrically separated from one another.
 4. The matrix displaydevice of claim 2, wherein said electrically conducting layer depositedon the second substrate forms one or more display pixel electrodesopposing the display pixel electrodes carried on the first substrate. 5.The matrix display device of claim 2, wherein said electricallyconducting layer deposited on the second substrate forms light shieldsextending between display pixels.
 6. The matrix display device of claim1, wherein electrical potentials are supplied to each of the separateareas of the shielding layer from the first substrate via respectiveelectrical connection elements extending between the first and secondsubstrates.
 7. The matrix display device of claim 1, wherein theauxiliary electronic circuitry is integrated circuitry comprising thinfilm circuit elements fabricated on the first substrate.
 8. The matrixdisplay device of claim 1, wherein the auxiliary electronic circuitrycomprises at least row and column drive circuits for driving the displaypixel array.
 9. The matrix display device of claim 1, wherein a seal isprovided between the first and second substrates extending around atleast the display area to contain the electro-optic material, andwherein at least part of the auxiliary electronic circuitry lies outsidethe seal line.
 10. The matrix display device of claim 9, wherein theseal is a first seal, the device comprising a second seal providedbetween The first and second substrates extending around the least partof The auxiliary electronic circuitry tat lies outside the first seal.11. The matrix display device of claim 1, wherein the device comprisesan active matrix liquid crystal display device.
 12. The matrix displaydevice of claim 1, wherein said auxiliary electronic circuitry comprisesa video signal processing circuit and said video signal processingcircuit performs corrections and adjustments to an incoming video signalprior to said incoming video signal being provided to a column drivecircuit.
 13. The matrix display device of claim 1, wherein saidauxiliary electronic circuitry further comprises a video control logiccircuit that derives timing information from the incoming video signaland provides control signals for operating row and column drive circuitson said matrix display device.
 14. The matrix display device of claim 1,wherein said auxiliary electronic circuitry comprises a memory circuitthat is for storing pixel data.
 15. The matrix display device of claim1, comprising a passivation layer deposited over a portion of theauxiliary electronic circuitry.
 16. The matrix display device of claim1, wherein the auxiliary electronic circuitry includes circuitry forsensing a touch input.
 17. A matrix display device comprising:electro-optic material disposed between a first substrate and a secondsubstrate; a plurality of pixel electrodes on a first side of said firstsubstrate, said first side of said first substrate facing said secondsubstrate, said plurality of pixel electrodes define display pixels in adisplay area; a video signal processing circuit in a region, on saidfirst side of said first substrate, separate from said display area;said second substrate extends over at least part of said video signalprocessing circuit and the display area; and an electrically conductiveshielding layer on a side of said second substrate for electricallyshielding at least a region of said video signal processing circuit,wherein said electrically conductive shielding layer is divided into aplurality of electrically separate areas covering respective parts ofsaid region of said video signal processing circuit.
 18. A matrixdisplay device comprising: electro-optic material disposed between afirst substrate and a second substrate; a plurality of pixel electrodesdisposed on a first side of said first substrate, said first side ofsaid first substrate facing said second substrate, said plurality ofpixel electrodes define display pixels in a display area; a specialtycircuit being one of a video signal processing circuit, a video controllogic circuit, and a memory circuit disposed in a region, on said firstside of said first substrate, separate from said display area; saidsecond substrate extends over at least part of said specialty circuitand the display area; and an electrically conductive shielding layer ona side of said second substrate for electrically shielding at least aregion of said specialty circuit, wherein said electrically conductiveshielding layer is divided into a plurality of electrically separateareas covering respective parts of said region of said specialtycircuit.
 19. The matrix display device of claim 18, wherein saidspecialty circuit receives an analog signal.
 20. A matrix display devicecomprising: electro-optic material disposed between a first substrateand a second substrate; a plurality of pixel electrodes on a first sideof said first substrate, said first side of said first substrate facingsaid second substrate, said plurality of pixel electrodes define displaypixels in a display area; a signal processing circuit comprising analogcircuitry for performing corrections and adjustments to an incomingvideo signal and for deriving timing information from the incoming videosignal, said signal processing circuit positioned in a region on saidfirst side of said first substrate that is outside of said display area;said second substrate extends over at least part of said analogcircuitry and the display area; and an electrically conductive shieldinglayer, on a side of said second substrate that faces said analogcircuitry, for electrically shielding at least a region of said analogcircuitry, wherein said electrically conductive shielding layer isdivided into aplurality of electrically separate areas coveringrespective parts of said signal processing circuit.